1. Technical Field
The present invention relates to electrically powered vehicles, control devices for electrically powered vehicles, and computer readable media.
2. Related Art
Electrically powered vehicles include hybrid vehicles driven by means of motors and engines, and electric vehicles driven by means of motors (refer to JP 2007-124746 A, JP 2007-120382 A, and JP 2007-143303 A, for example). Specifically, electrically powered vehicles include those in which an inverter is used to convert DC power into AC power, which is then supplied to a motor for travel to drive the motor.
In such electrically powered vehicles, when the motor normally rotates, AC current flows through respective elements (switching element, diode, etc.) of the inverter. However, when the motor is in a locked state (for example, stopped state or an ultra-low rotating state), a large DC current flows in a particular element of the inverter so that loss of the element increases, causing larger heat generation.
Among known configurations of electrically powered vehicles are those in which a DC voltage from a DC power source is boosted by a boost converter and the boosted DC voltage is supplied to the inverter. Configurations of this type are intended to realize higher motor output and to improve energy efficiency.
In such a configuration, because a voltage boosted by the boost converter is applied to the inverter, when the motor is in a locked state, a significantly large current flows through a particular element of the inverter, that element generates a great amount of heat.
In order to prevent this problem, JP 2007-124746 A proposes a technique to control output voltage of a boost converter when it is detected that a motor is in a locked state.